HOUSTON -- U.S. immigration officers have arrested more than 2,100 fugitive illegal immigrants in a nationwide sweep, officials announced Wednesday.

In a blitz that began May 26, U.S. Immigration and Customs Enforcement arrested 2,179 illegal immigrant gang members, pedophiles, violent felons and others who have sneaked back in the country after being deported.

"Roughly half had criminal convictions ranging from sexual assault of a minor to drug trafficking to assault with a deadly weapon to robbery and abduction," said Julie Myers, assistant secretary for ICE.

More than 360 were members or associates of violent gangs, including the notorious Mara Salvatrucha, or MS-13, she said.

Approximately 120 of the arrests were in Houston.

The arrests were the latest in a new enforcement effort announced in April by Homeland Security Secretary Michael Chertoff, Myers said.

"These operations are the result of the secretary's interior enforcement strategy and his mandate to me and to our agency to go out and get the job done in a way we haven't done it before," she said. "I think you are seeing that in the area of criminal aliens. You are seeing that in the area of work sites and you will see that in the area of human smuggling."

Myers said most of those arrested had been placed in deportation proceedings, and 829 had already been sent home. Another 121 arrested on criminal charges were to be sent through the federal court system.

"America's welcome does not extend to immigrants who come here to commit crimes," Myers said. "ICE will leave no stone unturned in hunting down and deporting aliens who victimize our communities.

"We're just doing our job enforcing the laws on the books," she said.

Among the more notorious criminals arrested was Angel Lira-Alvarez, a Mexican national living in Dallas and a member of the East Side Homeboys gang. He has been convicted and deported several times for drug dealing and burglary.

Asked if the operation was a result of the ongoing immigration reform debate in Congress, Myers said, "We're just doing our job. We're enforcing the laws on the books."

The day that Chertoff announced the new get-tough policy, April 20, immigration authorities raided a wooden pallet manufacturer in Houston and in about 40 other cities, rounding up 1,100 illegal immigrants. While most of the immigrants were let go, seven managers of IFCO Systems were arrested.

ICE has had similar operations in recent months, but on a much smaller scale.

In May, ICE officers in the Las Vegas area arrested 179 immigration violators, many of whom had outstanding orders of deportation or criminal records. The Houston ICE office deported 242 illegal immigrants with criminal records or who were immigration violators.

In April, immigration officers in the Midwest arrested 106 illegal immigrant fugitives during a 10-day operation, while ICE officers in Florida arrested 183 illegal immigrants, most of whom were fugitive criminals.

In February, ICE officers in Georgia, North Carolina and South Carolina deported 482 illegal immigrants, most of whom had criminal records.

California had the most number of arrests with 722. Texas was second with 424. In all, illegal immigrants were arrested in 34 states.

The immigrants arrested in Operation Return to Sender came from all over the world, including Africa, Asia, Latin America, Europe and the Middle East.

Myers said ICE would try to keep the deportees out of the United States this time.

"We will work with our foreign counterparts ... to prevent these individuals from returning. We're also on the lookout for them as well," Myers said.